The brain stem forms the first model that gathers inputs and filters the sensory data down so the 2nd level can receive organized input.

The 2nd level takes this sensory input (not sure if limbic system and hippocampus?) that then gathers concepts of things and ideas.

The 3rd level then gathers these concepts and ideas to make sense of them all toegether in terms of meaning while at the same time being aware they are being made sense of (self-awareness) which is the way we "think therefore I am" type deal.

In other words, our sense of who we are is a higher order computation mostly just information so we are a dream of our brain in other words if we put stock into that sense of self being who we really are.